1. Field of the Invention
The invention relates to a method of memory error correction by scrubbing.
2. Description of the Prior Art
A computer memory is usually equipped with hardware circuits which detect errors and repair them. To this end, Error Correction Code, here-after called "ECC", is used. The data in the computer memory contains information bits and redundant bits computed from the information bits. Such a code is capable of supplying correct (i.e. recovered) data to a particular processing element even if some bits of the data in the memory are corrupted. This mechanism provides a security reserve against the data loss.
The capability to correct corrupted data is primarily limited by the length of the redundant part of the data. Accordingly, once a data element contains some corrupted bits, there is not enough security reserve against additional bit corruption. Measures have to be taken to rewrite the corrupted data into the memory with a fresh and corrected copy. This later task is referred to as memory scrubbing.